高温后移对水稻颖花败育的影响

以籼稻Ⅱ优7954和Ⅱ优7号为供试材料,通过人工气候箱在水稻抽穗开花期进行两种高温处理,即常规38℃高温处理（9：00-14：00）和38℃高温后移处理（11：00-16：00）,以受精率衡量高温后移对水稻颖花败育的影响,并进一步探讨高温后移下颖花败育的原因.结果表明：常规高温处理下颖花育性对开花当天高温最敏感,而高温后移处理下颖花育性对开花前1d高温最敏感;高温后移开花高峰出现在高温来临前,可见高温后移主要通过开花前高温而非开花时高温影响颖花育性;开花前高温主要通过影响花药散粉、花粉粒萌发和花粉管延伸从而引起颖花败育.研究成果可为水稻品种高温热害鉴定提供科学依据.

Effects of High Temperature on Rice Spikelet Sterility at Flowering Stage

Two indica rice cultivars Ⅱ you 7954 and Ⅱ you 7 were used as materials.They were exposed at two high temperature stress treatments,which included conventional with 38℃ between 9：00 and 14：00,and delaying with 38℃ between 11：00 and 16：00 in phytotron,their response was quantified at flowering stage through spikelet fertility.The results showed that rice spikelet sterility was highest sensitive to conventional high temperature treatment on the same day of flowering,and highest sensitive to delaying high temperature treatment on the previous day of flowering.The flowering peak delaying high temperature treatment occurred before 11：00am,which meant rice spikelet sterility was induced by high temperature before flowering,but not at flowering.Rice spikelet sterility induced by high temperature during 11：00-16：00 was mainly due to effects on anther dehiscence,pollen germination and tube growth.The results could provide references to evaluate rice resistance to heat.